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Distribution of Life Distribution of Life

in the Oceansin the Oceans

Here, There, and Here, There, and

Almost EverywhereAlmost Everywhere

�� PelagicPelagic refers to the refers to the water columnwater column

from surface to the just above the bottomfrom surface to the just above the bottom

�� BenthicBenthic refers to the refers to the seafloorseafloor

from salt marsh to the deepest trenchfrom salt marsh to the deepest trench

�� There are many moreThere are many more benthicbenthic species of animals than species of animals than pelagic speciespelagic species

~98% of all marine animal species live on or near the seafloor~98% of all marine animal species live on or near the seafloor

nekton(active swimmers)

plankton (passive floaters)

benthon (bottom-dwellers)

epifaunainfauna

benthicbenthic

pelagicpelagic

Ocean habitatsOcean habitats

Mr. Ray sings …Mr. Ray sings …

““OoohOooh, let's name the zones, the zones, the zones, , let's name the zones, the zones, the zones,

Let's name the zones of the open sea!Let's name the zones of the open sea!

MesopolagicMesopolagic, bathypelagic, , bathypelagic, abyssalpelagicabyssalpelagic, ,

All the rest are too deep for you and me to see.”All the rest are too deep for you and me to see.”

Ocean habitats (“Ocean habitats (“biozonesbiozones”)”)

�� the the pelagicpelagic (water column) environments(water column) environments�� broad: broad:

�� neriticneritic zone zone –– overlies continental shelfoverlies continental shelf

�� oceanic zone oceanic zone –– beyond shelf breakbeyond shelf break

�� specific: specific: �� epipelagic epipelagic zonezone

–– illuminated surface layerilluminated surface layer

�� mesopelagicmesopelagic zonezone–– “twilight,” no photosynthesis“twilight,” no photosynthesis

�� bathypelagic zonebathypelagic zone–– totally dark, no living plantstotally dark, no living plants

�� abyssalpelagic abyssalpelagic zonezone–– more than ½ ocean volumemore than ½ ocean volume

�� hadalpelagic hadalpelagic zonezone–– deepdeep--sea trenchessea trenches

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Ocean habitats (“Ocean habitats (“biozonesbiozones”)”)

�� the the benthicbenthic (bottom) environments(bottom) environments�� shallow (shelf):shallow (shelf):

�� littoral (littoral (intertidalintertidal) zone ) zone –– between high and low tidebetween high and low tide

�� sublittoralsublittoral zone zone –– beach to shelf breakbeach to shelf break

�� deep:deep:�� bathyalbathyal zonezone

–– continental slope & risecontinental slope & rise

–– beneath beneath mesopelagicmesopelagic and and bathypelagic zonesbathypelagic zones

�� abyssal zoneabyssal zone–– average deep ocean bottomaverage deep ocean bottom

–– beneath beneath abyssalpelagic abyssalpelagic zonezone

�� hadalhadal zonezone–– deepdeep--sea trenchessea trenches

–– beneath beneath hadalpelagic hadalpelagic zonezone

�� epipelagic epipelagic zonezone

–– illuminated surface layerilluminated surface layer

�� mesopelagicmesopelagic zonezone–– “twilight,” no photosynthesis“twilight,” no photosynthesis

�� bathypelagic zonebathypelagic zone–– totally dark, no living plantstotally dark, no living plants

�� abyssalpelagic abyssalpelagic zonezone–– more than ½ ocean volumemore than ½ ocean volume

�� hadalpelagic hadalpelagic zonezone–– deepdeep--sea trenchessea trenches

photicphoticzonezone

aphoticaphoticzonezone

dysphoticdysphoticzonezone

Light penetration zonesLight penetration zones

�� photicphotic zonezone –– depth where light is sufficient for photosynthesisdepth where light is sufficient for photosynthesis

�� dysphoticdysphotic zonezone –– depth where illumination is too weak for depth where illumination is too weak for

photosynthesisphotosynthesis

�� aphoticaphotic zonezone –– receives no light from the surface because it is receives no light from the surface because it is

all absorbed by the water aboveall absorbed by the water above

Some termsSome terms

�� HeterotrophsHeterotrophs -- organisms that organisms that require foodrequire foodin the form of organic compounds prefabricated in the form of organic compounds prefabricated by other organismsby other organisms

�� AutotrophsAutotrophs -- organisms that can organisms that can synthesizesynthesizeorganicorganic compounds (their body tissues) from compounds (their body tissues) from inorganicinorganic substances (nutrients)substances (nutrients)�� that is, they make their own foodthat is, they make their own food

�� two types:two types:1.1. photosynthetic organisms photosynthetic organisms

�� utilize utilize solar energysolar energy to power to power photosynthesisphotosynthesis

�� live in the live in the photic photic zonezone

2.2. chemosyntheticchemosynthetic organisms organisms �� utilize utilize chemical reactionschemical reactions to power to power chemosynthesischemosynthesis

�� commonly live near deep sea ventscommonly live near deep sea vents

Plankton Plankton –– “passive floaters”“passive floaters”

�� phytoplanktonphytoplankton -- microscopic, singlemicroscopic, single--celled, photosynthetic celled, photosynthetic algae (diatoms, algae (diatoms, dinoflagellatesdinoflagellates, , coccolithophoridscoccolithophorids))

�� zooplanktonzooplankton -- includes some animals (copepods, krill, jellies) includes some animals (copepods, krill, jellies) and microscopic, singleand microscopic, single--celled intermediate plant/animal life celled intermediate plant/animal life forms (flagellates, ciliates, forms (flagellates, ciliates, foramsforams))

�� bacterioplanktonbacterioplankton -- many kinds of many kinds of heterotrophicheterotrophic bacteria, and bacteria, and some photosynthetic bacteria (some photosynthetic bacteria (cyanobacteriacyanobacteria))

�� meroplanktonmeroplankton -- larval stage of somelarval stage of some benthonicbenthonic and nektonic and nektonic animals (spend early part of life as plankton)animals (spend early part of life as plankton)

planktonplankton(passive floaters)(passive floaters)

nekton(active swimmers)

benthon (bottom-dwellers)

epifaunainfauna

benthic

pelagic

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DiatomDiatom(single(single--celled alga; here in a chain)celled alga; here in a chain)

Note the green color due to the presence of chlorophyll

Phytoplankton (mostly Phytoplankton (mostly colonial diatoms here)colonial diatoms here)

TrichodesmiumTrichodesmiumfilamentous filamentous cyanobacteriumcyanobacterium

ShrimpShrimp--like krilllike krillCopepodsCopepods are fleaare flea--sizedsizedcrustaceans; they are thecrustaceans; they are the

most abundant animal in themost abundant animal in theocean!ocean!

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members of themembers of thezooplanktonzooplanktoncommunitycommunity

ctenophoresctenophores jellyfishjellyfish

other gelatinousother gelatinousplanktonplankton

Portuguese manPortuguese man--oo--warwar

jellyfish & ctenophorejellyfish & ctenophore

jellyfish stranded on shorejellyfish stranded on shorePhysophoraPhysophora(a (a siphonophoresiphonophore))

Bolinopsis

Ctenophores

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AequoreaAequorea

PandeaPandea

BenthocondonBenthocondon

MeroplanktonMeroplanktonpartpart--time plankton:time plankton:

larval stages oflarval stages ofbenthonicbenthonic& nektonic& nektonic

invertebrate &invertebrate &vertebrate animalsvertebrate animals

newly hatched squid larvaenewly hatched squid larvaebarnacle larvabarnacle larva

jellyfish larvajellyfish larva

sea urchin larvasea urchin larva

MeroplanktonMeroplankton

MeroplanktonMeroplankton

crab larvacrab larva shrimp larvashrimp larva

peanut worm larvapeanut worm larva

shrimp or lobster larvashrimp or lobster larva

crab larvacrab larva

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MOCNESSMOCNESS plankton towplankton tow((MMultiple ultiple OOpening/pening/CClosing losing NNetetand and EEnvironmental nvironmental SSampling ampling SSystemystem

MOCNESS Plankton TowMOCNESS Plankton Tow

plankton netsplankton nets

Deck incubator for studiesDeck incubator for studiesof living planktonof living plankton

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Nekton Nekton –– “active swimmers”“active swimmers”

�� organisms capable of moving independently organisms capable of moving independently of ocean currentsof ocean currents

�� some invertebrates (squid)some invertebrates (squid)

�� many marine vertebrates (pelagic fish, many marine vertebrates (pelagic fish, marine mammals, marine reptiles)marine mammals, marine reptiles)

nektonnekton(active swimmers)(active swimmers)

plankton (passive floaters)

benthon (bottom-dwellers)

epifaunainfauna

benthic

pelagic

puffer fishpuffer fish

yellowyellow--fin tunafin tuna

giant sunfishgiant sunfishred tail wrassered tail wrasse

blueblue--spotted wrassespotted wrasse

Red Sea surgeonfishRed Sea surgeonfish

blue tang surgeonfishblue tang surgeonfish

yellow belly damselfishyellow belly damselfish

Great White SharkGreat White Shark

Reef SharkReef Shark

Whale SharkWhale Shark

Hammerhead SharksHammerhead Sharks

skatesskates

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Gray WhaleGray Whale

Humpback WhalesHumpback Whales

Harbor SealHarbor Seal“Flipper”“Flipper”

Leatherback turtleLeatherback turtle

NautilusNautilus

Benthon Benthon –– “bottom“bottom--dwellers”dwellers”

�� organisms that live on the seafloor (organisms that live on the seafloor (epifaunaepifauna & & epifloraepiflora) or ) or

buried within sediments (buried within sediments (infaunainfauna):):

�� most marine invertebrates (clams, mussels, oysters, snails, most marine invertebrates (clams, mussels, oysters, snails,

barnacles, lobsters, crabs, sea urchins, starfish, sea cucumbersbarnacles, lobsters, crabs, sea urchins, starfish, sea cucumbers, ,

corals, anemones, sponges, worms)corals, anemones, sponges, worms)

�� attached plants (sea grasses) and algae (kelp and other attached plants (sea grasses) and algae (kelp and other

seaweeds)seaweeds)

�� “ground fish” (flounder, sole, cod, haddock)“ground fish” (flounder, sole, cod, haddock)

nekton(active swimmers)

plankton (passive floaters)

benthonbenthon(bottom(bottom--dwellers)dwellers)

epifaunaepifaunainfaunainfauna

benthic

pelagic

anemones (anemones (epifaunaepifauna))

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Brittle starBrittle star

Giant tube wormGiant tube worm

Giant clamGiant clam

abaloneabalone scallopscallop

Environmental controls on distributionEnvironmental controls on distribution

�� lightlight

�� temperaturetemperature

�� salinitysalinity

�� food availabilityfood availability

�� water densitywater density

�� water viscositywater viscosity

�� dissolved nutrientsdissolved nutrients

�� pollutionpollution

�� space to livespace to live

�� covercover

�� habitathabitat

�� our focus …our focus …

�� temperaturetemperature

�� salinitysalinity

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�� RatesRates of diffusion, osmosis, and metabolism are strongly of diffusion, osmosis, and metabolism are strongly temperaturetemperature--dependentdependent..

The higher the temperature, the higher the The higher the temperature, the higher the rate ofrate of molecular molecular movementmovement into or out of cells, and the higher the into or out of cells, and the higher the rate of biological rate of biological activityactivity including growth rates, motility, and life span.including growth rates, motility, and life span.

�� Temperature also controls the Temperature also controls the concentration of dissolved concentration of dissolved gasesgases in water (COin water (CO22 for photosynthesis, Ofor photosynthesis, O22 for animal for animal respiration)respiration)

The higher the temperature, the less dissolved gas that water caThe higher the temperature, the less dissolved gas that water can n hold hold (i.e., cold water holds more dissolved gas)(i.e., cold water holds more dissolved gas)

�� StenothermalStenothermal organisms can tolerate only a organisms can tolerate only a narrownarrowrange of temperatures (deep and/or mobile organisms)range of temperatures (deep and/or mobile organisms)

�� EurythermalEurythermal organisms can tolerate a organisms can tolerate a widerwider range of range of temperatures (shallow and/or sessile organisms)temperatures (shallow and/or sessile organisms)

Effects of TemperatureEffects of Temperature Effects of SalinityEffects of Salinity

�� SalinitySalinity is an important control on the distribution of is an important control on the distribution of

organisms because of organisms because of osmotic pressureosmotic pressure..

�� StenohalineStenohaline organisms can tolerate only a narrow range organisms can tolerate only a narrow range

of salinity (deep and/or mobile organisms).of salinity (deep and/or mobile organisms).

Many organisms are not be able to tolerate the high salinities Many organisms are not be able to tolerate the high salinities (>40(>40‰‰) of some subtropical lagoons or the reduced salinities ) of some subtropical lagoons or the reduced salinities (<30 (<30 ‰‰) of coastal waters or estuaries) of coastal waters or estuaries

�� EuryhalineEuryhaline organisms can tolerate a wider range of organisms can tolerate a wider range of

salinities (surface and/or sessile organisms).salinities (surface and/or sessile organisms).

Coastal organismsCoastal organisms must be able to cope with daily and seasonal must be able to cope with daily and seasonal swings in salinity related to tidal movement, evaporation, preciswings in salinity related to tidal movement, evaporation, precipitation pitation and river runoffand river runoff

MidMid--Latitude Latitude Intertidal Intertidal

CommunitiesCommunities

DeepDeep--sea vent sea vent CommunitiesCommunities

TemperatureTemperature

SalinitySalinity

Environmental Environmental Tolerance of Tolerance of

Marine Marine OrganismsOrganisms

EuryEury--thermalthermal

EuryEury--halinehaline

StenoSteno--thermalthermal

StenoSteno--halinehaline

Diffusion and OsmosisDiffusion and Osmosis

�� Seawater poses a special problem for many marine organisms Seawater poses a special problem for many marine organisms because of a difference in because of a difference in ionic concentrationionic concentration ((salinitysalinity) ) between the body fluids of an organism and its salt water between the body fluids of an organism and its salt water environment.environment.

�� Cell walls are Cell walls are semisemi--permeablepermeable; some molecules pass ; some molecules pass through, others are screened out.through, others are screened out.

�� DiffusionDiffusion is the passive movement of molecules is the passive movement of molecules from high from high concentration to low concentrationconcentration to low concentration..

�� OsmosisOsmosis is the is the diffusion of water moleculesdiffusion of water molecules into or out of a into or out of a cell.cell.

�� If there is a difference, or gradient, between the inside and If there is a difference, or gradient, between the inside and outside of the cell, an osmotic pressure will cause water outside of the cell, an osmotic pressure will cause water molecules to move molecules to move �� fromfrom high concentration of water (=low salinity) high concentration of water (=low salinity)

�� toto low concentration of water (=high salinity).low concentration of water (=high salinity).

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nutrient moleculesnutrient molecules

waste moleculewaste molecule

diffusion: highconcentration →→→→ low concentration

nutrients move intothe cell, wastes move out

cell membranecell membrane

Diffusion occurs on any concentration gradient Diffusion occurs on any concentration gradient across a cell membrane, including the across a cell membrane, including the regulation of nutrients and waste regulation of nutrients and waste prodcutsprodcuts.. Osmotic PressureOsmotic Pressure

�� Cells and tissue having an ionic concentration Cells and tissue having an ionic concentration lessless than than

the seawater they live in: the seawater they live in: hypotonichypotonic

�� many salt water fish and marine mammalsmany salt water fish and marine mammals have evolved have evolved strategies to overcome the strategies to overcome the loss of waterloss of water ((dehydrationdehydration) from ) from their cellstheir cells

�� Cells and tissue having an ionic concentration Cells and tissue having an ionic concentration greater greater

than the environment they live in: than the environment they live in: hypertonichypertonic

�� fresh water fishfresh water fish have evolved strategies to rid themselves of have evolved strategies to rid themselves of excess waterexcess water from their cellsfrom their cells

�� Cells and tissue with an Cells and tissue with an ionic concentration equalionic concentration equal to theto the

environment they live in: environment they live in: isotonicisotonic

�� sharks, rays, and many marine invertebratessharks, rays, and many marine invertebrates

Na+

Cl -

Na+

Cl -

Na+

Cl -

Na+

Cl -

HCO-3

Ca+2

K+

Mg +2

SO4-2

Ca+2

HCO-3

salinity outside > salinity inside(water is more concentrated on the inside of the cell relative to “salts”)

water moves outof the cell

hypotonichypotonic cellcellas in marine fishas in marine fish

Thought experimentThought experiment

Below is a fish tank which is divided into two parts; a Below is a fish tank which is divided into two parts; a

semipermeable semipermeable membrane separates the two halves. The left membrane separates the two halves. The left

side contains fresh water and the right side contains salt waterside contains fresh water and the right side contains salt water. .

An osmotic pressure exists across the membrane barrier.An osmotic pressure exists across the membrane barrier.

0 /ooo 35 /o

oomovement of water molecules?

which side represents theconditions that would affect

a fresh water fish?

which side represents theconditions that would affect

a salt water fish?

and if wedrink

salt water?